ABSTRACT
RESUMO Objetivo: Avaliar o relacionamento entre os níveis cerebrais de ferro e heme e a resposta inflamatória sistêmica e no sistema nervoso central, assim como o papel dos sistemas de defesa contra a toxicidade do ferro e do heme, no sistema nervoso central. Métodos: Avaliamos uma coorte prospectiva de pacientes com quadro de hemorragia intracraniana e subaracnóidea. Realizamos ensaios em amostras de plasma e líquido cefalorraquidiano quanto à presença de ferro, heme, hemopexina, haptoglobina, enolase, S100-β e citocinas nos primeiros 3 dias após um acidente vascular cerebral hemorrágico. Analisamos também as alterações dinâmicas em todos os componentes de ambos os líquidos e seu relacionamento com as taxas de mortalidade precoce. Resultados: As concentrações de hemopexina e haptoglobina foram quase desprezíveis no cérebro após hemorragia intracraniana e subaracnóidea. As concentrações de ferro e heme no líquido cefalorraquidiano se correlacionaram com resposta pró-inflamatória no sistema nervoso central, e os perfis inflamatórios no líquido cefalorraquidiano no terceiro dia após acidente vascular cerebral hemorrágico se correlacionaram com as taxas de mortalidade precoce. Identificamos que os níveis de interleucina 4 no líquido cefalorraquidiano durante as primeiras 24 horas após acidente vascular cerebral hemorrágico foram mais altos nos sobreviventes do que nos que não sobreviveram. Conclusão: Os níveis de ferro e heme se associaram com resposta pró-inflamatória no sistema nervoso central após acidente vascular cerebral hemorrágico, e o cérebro humano não tem proteção contra hemoglobina e heme. Os perfis inflamatórios dos pacientes se associaram com prognósticos piores, e as respostas inflamatórias locais pareceram ter um papel protetor.
ABSTRACT Objective: To evaluate the relationships of brain iron and heme with the inflammatory response of the systemic and central nervous systems and to investigate the role of defensive systems against the toxicity of iron and heme in the central nervous system. Methods: We assessed a prospective cohort of patients presenting with intracerebral and subarachnoid hemorrhage. We assayed plasma and cerebrospinal fluid samples for the presence of iron, heme, hemopexin, haptoglobin, enolase, S100-β and cytokines for the first three days following hemorrhagic stroke. We also analyzed the dynamic changes in these components within both fluids and their relationship with early mortality rates. Results: Hemopexin and haptoglobin concentrations were nearly negligible in the brain after intracerebral and subarachnoid hemorrhage. Cerebrospinal fluid iron and heme concentrations correlated with a pro-inflammatory response in the central nervous system, and plasmatic and cerebrospinal fluid inflammatory profiles on the third day after hemorrhagic stroke were related to early mortality rates. Interleukin 4 levels within the cerebrospinal fluid during the first 24 hours after hemorrhagic stroke were found to be higher in survivors than in non-survivors. Conclusion: Iron and heme are associated with a pro-inflammatory response in the central nervous system following hemorrhagic stroke, and protections against hemoglobin and heme are lacking within the human brain. Patient inflammatory profiles were associated with a poorer prognosis, and local anti-inflammatory responses appeared to have a protective role.
Subject(s)
Humans , Male , Female , Aged , Subarachnoid Hemorrhage/physiopathology , Hemoglobins/metabolism , Cerebral Hemorrhage/physiopathology , Stroke/physiopathology , Brain/physiopathology , Hemopexin/metabolism , Prospective Studies , Cohort Studies , Heme/metabolism , Inflammation/physiopathology , Middle AgedABSTRACT
Objective To explore the potential effects of endothelial progenitor cells (EPCs)-angiogenesis on mechanism of alleviating cognitive dysfunction in rats subjected to cerebral ischemia-reperfusion (I/R) injury. Methods A total of 121 male Sprague–Dawley (SD) rats were randomly divided into four groups:Sham group (n=31), focal I/R(MCAO, 0.9%saline 10μL, n=30) group, MCAO+Vehicle (sodium azide, 0.1%Vehicle 10μL, n=30) group and MCAO+HPX (1.86 g/L HPX 10μL, n=30) group. The modified neurological severity scores (mNSS) was carried out to determine neurological function deficit after I/R. Morris water maze (MWM) was carried out to assess learning and memory abilities after I/R. The circulating EPCs after I/R were counted by flowcytometry (FCM) combined with double-immunofluorescence staining of CD34 and CD133. Angiogenesis in rat penumbra cortex after I/R was assessed by immunohistochemical technique combined with immunofluorescent chromogenic detection of CD31 and vWF. Results Compared with sham group, the mNSS scores, the escape latency and the circulating EPCs count were increased after I/R, the time percentage spent in target quadrant was reduced, and the new vessel density in penumbra cortex was increased after I/R in MCAO group (P 0.05). The mNSS score and the escape latency were significantly decreased, the circulating EPCs count and new vessel density in penumbra cortex were significantly increased after I/R in MCAO+HPX group compared with those of MCAO+Vehicle and MCAO group (P<0.05). Conclusion EPCs-angiogenesis signaling plays positive effects on HPX alleviating cognitive dysfunction in rats subjected to focal cerebral ischemia reperfusion injury.
ABSTRACT
Matrix metalloproteinases-9 (MMP-9) is an important cancer-associated, zinc-dependent endopeptidase. To investigate the natural selection hypothesis of MMP-9, the orthologous sequences from 12 vertebrates were compared and a molecular evolution analysis was performed. Results suggest that amino acid residues present in the middle region of the protein are more selectively constrained, whereas amino acid residues in the C-terminal region of the MMP-9 protein including exon 13 showed lowest conservation level in non-primate species, suggesting that it is an exon with fast evolving rate compared to the others analyzed. InterProScan analysis shows that exon 13 was located in hemopexin (PEX) domain of MMP-9. Positive selection was detected in PEX domain of MMP-9 protein between human and other species, which indicates that selective pressure may play a role in shaping the function of MMP-9 in the course of evolution.